Close-up: Guy and Max Shepherd

Few people in the world are immune to the charms of a diamond. Nevertheless, it took Guy Shepherd the best part of a decade to convince his brother Max to give up his interior-design career and join the family jewellery business. Now the duo are causing a stir in London's fine-jewellery scene with their Guy&Max brand, offering a contemporary spin on traditional luxury.

"Our father has been in the wholesale diamond industry for years," explains 35-year-old Guy. "To me, he was James Bond." But for Max, 34, the idea of creating rings and necklaces went against his design instinct: "The fact that jewellery is purely decorative was a problem for me."

It took a stint helping out in their father's Hatton Garden workshop four years ago to persuade him that fine jewellery needn't be boring. "We realised Max could scale down his ideas from interiors and furniture to diamonds and platinum," says Guy.

"Architecture is my main inspiration," explains Max. "I work with computer programs normally used for designing buildings. That means lots of straight lines, so now I'm experimenting with the animation programs used in the Spider-Man films to find more organic shapes." So far, Max's technical wizardry has resulted in unusual geometric forms such as his signature pavé diamond cube-shaped rings.

Such an offbeat approach in an industry known for its conservatism seems risky, especially given the state of the economy. Their Mayfair flagship store, however, has just enjoyed its best sales month yet. "We're still pinching ourselves," admits Guy. "But thankfully, no matter what, people still fall in love, get engaged and celebrate birthdays."